JP2016208164A - Communication device, communication system, and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication device capable of controlling output level in a short time and with high accuracy.SOLUTION: A communication device includes: a reception section for generating a first level control signal on the basis of input level of a first data signal and the number of errors; and a transmission section for transmitting the first level control signal.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a communication device that exchanges data, a communication system including such a communication device, and a communication method used in such a communication system.

  As electronic devices become more sophisticated and multifunctional in recent years, electronic devices have begun to exchange more information with other electronic devices. For example, electronic devices are often connected to other electronic devices by wired communication. In wired communication, an optical fiber is often used when more data is exchanged.

  In optical communication using an optical fiber, the output level of an optical signal output from a transmitter is often controlled. For example, Patent Documents 1 and 2 disclose communication systems that control an output level in a transmission device based on an input level in a reception device. Further, for example, Patent Document 3 discloses a communication system that controls the output level in the transmission device based on the error rate measured by the reception device.

JP 2010-154375 A JP 2004-32476 A Japanese Patent Laid-Open No. 2002-164846

  In such a communication system, it is desired to control the output level of the optical signal output from the transmission apparatus with high accuracy. It is also expected to control the output level in a short time.

  The present disclosure has been made in view of such problems, and an object thereof is to provide a communication device, a communication system, and a communication method capable of controlling an output level in a short time and with high accuracy.

  The communication device according to the present disclosure includes a reception unit and a transmission unit. The receiving unit generates the first level control signal based on the input level of the first data signal and the number of errors. The transmission unit transmits the first level control signal.

  The communication system according to the present disclosure includes a first communication device and a second communication device. The first communication device includes: a first receiving unit that receives the first level control signal; and a first transmitting unit that transmits the first data signal at an output level corresponding to the first level control signal. It is what you have. The second communication device receives the first data signal, and generates a first level control signal based on the input level and the number of errors of the first data signal, And a second transmitter for transmitting the level control signal.

  The communication method according to the present disclosure causes the first communication device to receive the first level control signal and to transmit the first data signal at an output level corresponding to the first level control signal. The apparatus receives the first data signal, generates the first level control signal based on the input level of the first data signal and the number of errors, and transmits the first level control signal. .

  In the communication device, the communication system, and the communication method of the present disclosure, the first level control signal is generated and transmitted based on the first data signal. The first level control signal is generated based on the input level of the first data signal and the number of errors.

  According to the communication device, the communication system, and the communication method of the present disclosure, the first level control signal is generated based on the input level and the number of errors of the first data signal. The output level can be controlled. In addition, the effect described here is not necessarily limited, and there may be any effect described in the present disclosure.

1 is a block diagram illustrating a configuration example of a communication system according to an embodiment of the present disclosure. FIG. 2 is a block diagram illustrating a configuration example of a transmission unit illustrated in FIG. 1. FIG. 2 is a block diagram illustrating a configuration example of a receiving unit illustrated in FIG. 1. FIG. 4 is a block diagram illustrating a configuration example of a control signal generation unit illustrated in FIG. 3. 3 is a flowchart illustrating an operation example of the communication system illustrated in FIG. 1. It is explanatory drawing showing the example of 1 operation | movement of the communication system shown in FIG. FIG. 10 is another explanatory diagram illustrating an operation example of the communication system illustrated in FIG. 1. It is explanatory drawing showing the operation example of the control signal generation part which concerns on a modification. It is a block diagram showing the example of 1 structure of the communication system which concerns on another modification. FIG. 10 is an explanatory diagram illustrating an operation example of the communication system illustrated in FIG. 9. FIG. 10 is another explanatory diagram illustrating an operation example of the communication system illustrated in FIG. 9.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[Configuration example]
FIG. 1 illustrates a configuration example of a communication system (communication system 1) according to an embodiment. The communication system 1 performs communication using optical signals. The communication method according to the embodiment of the present disclosure is embodied by the present embodiment, and will be described together.

  The communication system 1 includes a transmission cable 90, a transmission device 10, and a reception device 20. The transmission device 10 and the reception device 20 are connected to each other via a transmission cable 90.

  The transmission cable 90 includes an optical fiber 901, electric wires 902 and 903, and connectors 91 and 92. The optical fiber 901 transmits a data signal from the transmission device 10 to the reception device 20. The electric wire 902 is used by the transmitting device 10 and the receiving device 20 to detect the connection between them. The electric wire 903 transmits a control signal CTL1 (described later) from the receiving device 20 to the transmitting device 10. The connector 91 is provided at one end of the transmission cable 90 and is configured to be coupled to the connector 11 of the transmission device 10. The connector 92 is provided at the other end of the transmission cable 90 and is configured to be coupled to the connector 21 of the receiving device 20.

(Transmitter 10)
The transmission device 10 transmits a data signal to the reception device 20 via the optical fiber 901. The transmission device 10 includes a connector 11, a processing unit 12, a transmission unit 30, a light emitting unit 14, a connection detection unit 15, and a reception unit 16.

  The connector 11 is configured to be coupled to the connector 91 of the transmission cable 90.

  The processing unit 12 generates data INF1 and control data INFC1 by performing predetermined processing, and supplies the data INF1 and control data INFC1 to the transmission unit 30.

  The transmission unit 30 generates the data signal S30 based on the data INF1, the control data INFC1, and the detection signal DET1. The transmission unit 30 also has a function of controlling the output level Lout of the optical signal output from the light emitting unit 14 using the signal S36 based on the control signal CTL1.

  FIG. 2 illustrates a configuration example of the transmission unit 30. In this figure, in addition to the transmission unit 30, the processing unit 12 and the light emitting unit 14 are also drawn. The transmission unit 30 includes error correction encoding units 31 and 32, a frame generation unit 33, an initial output level storage unit 34, an output level range storage unit 35, and an output level control unit 36.

  The error correction encoding unit 31 generates an error correction code of the data INF1 by performing error correction encoding processing based on the data INF1. Then, the error correction encoding unit 31 supplies the generated error correction code to the frame generation unit 33 together with the data INF1. Similarly, the error correction encoding unit 32 generates an error correction code of the control data INFC1 by performing an error correction encoding process based on the control data INFC1. Then, the error correction encoding unit 32 supplies the generated error correction code to the frame generation unit 33 together with the control data INFC1.

  The frame generation unit 33 includes the data INF1 supplied from the error correction encoding unit 31, the error correction code of the data INF1, the control data INFC1 supplied from the error correction encoding unit 32, and the error correction code of the control data INFC1. Based on the above, a frame is generated. The frame generation unit 33 supplies the frame to the light emitting unit 14 using the data signal S30.

  The initial output level storage unit 34 stores an initial output level Lo_init of the optical signal output from the light emitting unit 14. This initial output level Lo_init is the output level Lout of the optical signal to be output by the light emitting unit 14 at the start of communication. The output level range storage unit 35 stores the range Lo_range of the output level Lout of the optical signal output from the light emitting unit 14.

  The output level control unit 36 controls the output level Lout of the optical signal output from the light emitting unit 14 based on the control signal CTL1 using the signal S36. At this time, the output level control unit 36 controls the output level Lout within the range Lo_range. The output level control unit 36 sets the output level Lout to the initial output level Lo_init at the start of communication.

  With this configuration, the transmission unit 30 generates the data signal S30 based on the data INF1 and the control data INFC1, and controls the output level Lout using the signal S36 based on the control signal CTL1. The transmission unit 30 starts such a transmission operation based on the detection signal DET1.

  The light emitting unit 14 converts an electrical signal (data signal S30) into an optical signal and outputs the optical signal, and includes, for example, a laser diode. The light emitting unit 14 changes the output level Lout of the optical signal based on the signal S36.

  The connection detection unit 15 detects whether or not the transmission device 10 and the reception device 20 are connected to each other. Specifically, the connection detection unit 15 connects the transmission device 10 and the reception device 20 to each other based on whether or not the connection detection unit 15 is connected to a connection detection unit 25 (described later) of the reception device 20 via the electric wire 902. It is designed to detect whether or not. The connection detection unit 15 notifies the transmission unit 30 of the detection result using the detection signal DET1.

  The receiving unit 16 receives the control signal CTL1 transmitted from the receiving device 20 via the electric wire 903. The receiving unit 16 supplies the control signal CTL1 to the transmitting unit 30.

(Receiver 20)
The receiving device 20 receives a data signal transmitted from the transmitting device 10 via the optical fiber 901. The receiving device 20 includes a connector 21, a light receiving unit 22, a receiving unit 40, a processing unit 24, a connection detecting unit 25, and a receiving unit 26.

  The connector 21 is configured to be coupled to the connector 92 of the transmission cable 90.

  The light receiving unit 22 generates the data signal S22 by converting the optical signal transmitted from the transmission device 10 into an electrical signal, and includes, for example, a photodiode.

  The receiving unit 40 generates data INF2 and control data INFC2 based on the data signal S22 and the detection signal DET2. The receiving unit 40 also has a function of generating the control signal CTL1.

  FIG. 3 illustrates a configuration example of the receiving unit 40. In this figure, in addition to the receiving unit 40, the light receiving unit 22 and the processing unit 24 are also drawn. The reception unit 40 includes control signal generation units 50 and 60, a frame separation unit 41, error correction decoding units 42 and 43, and a control signal generation unit 47.

  The control signal generation unit 50 generates a control signal CTLA based on the data signal S22. The control signal generation unit 50 includes an input level detection unit 51, a target input level storage unit 52, an input level comparison unit 53, and a loop filter 54. The input level detection unit 51 detects the input level Lin (Li_det) of the optical signal received by the light receiving unit 22 based on the data signal S22. The target input level storage unit 52 stores a target value (target input level Li_target1) of the input level Lin during normal operation. The input level comparison unit 53 obtains a difference DA between the input level Li_det and the target input level Li_target1. The loop filter 54 generates the control signal CTLA by smoothing the difference DA.

  Based on the data signal S22, the frame separation unit 41 extracts the data and the error correction code of the data from the frame included in the data signal S22 and supplies the data to the error correction decoding unit 42. An error correction code of control data is taken out and supplied to the error correction decoding unit 43.

  The error correction decoding unit 42 generates data INF2 by performing error correction decoding processing based on the data supplied from the frame separation unit 41 and the error correction code of the data. The error correction decoding unit 42 also has a function of counting the number of errors in a predetermined period and supplying the count result to the control signal generation unit 60. Similarly, the error correction decoding unit 43 generates control data INFC2 by performing error correction decoding processing based on the control data supplied from the frame separation unit 41 and the error correction code of the control data. It is. The error correction decoding unit 43 also has a function of counting the number of errors in a predetermined period and supplying the count result to the control signal generation unit 60.

  The control signal generation unit 60 generates the control signal CTLB based on the count result supplied from the error correction decoding units 42 and 43. The control signal generation unit 60 includes an error rate estimation unit 61, a target error rate storage unit 62, an input level comparison unit 63, and a loop filter 64. The error rate estimation unit 61 estimates the error rate BER (BER_est) in the communication system 1 based on the count result supplied from the error correction decoding units 42 and 43. The target error rate storage unit 62 stores a target value (target error rate BER_target) of the error rate BER in the communication system 1. The input level comparison unit 63 converts the error rate BER_est into the input level Lin (Li_est) based on a predetermined function indicating the relationship between the error rate BER and the input level Lin, and also converts the target error rate BER_target into the input level Lin ( Target input level Li_target2) to obtain a difference DB between the input level Li_est and the target input level Li_target2. The loop filter 64 generates the control signal CTLB by smoothing the difference DB.

  The control signal generator 47 generates the control signal CTL1 based on the control signals CTLA and CTLB.

  FIG. 4 illustrates a configuration example of the control signal generation unit 47. The control signal generation unit 47 has a selector 48 and a timer 49. The selector 48 outputs the control signal CTLA as the control signal CTL1 when the signal SEL is at the low level (L), and outputs the control signal CTLB as the control signal CTL1 when the signal SEL is at the high level (H). Is output as Based on the detection signal DET2, the timer 49 sets the signal SEL to a low level (until a predetermined time t_timer has elapsed from the timing when the connection detection unit 25 detects that the transmission device 10 and the reception device 20 are connected to each other). L), and then the signal SEL is set to a high level (H). Thereby, the control signal generation unit 47 outputs the control signal CTLA as the control signal CTL1 until a predetermined time t_timer elapses from the timing when the transmission device 10 and the reception device 20 are connected to each other, and thereafter, the control signal CTLB Is output as a control signal CTL1.

  With this configuration, the receiving unit 40 generates the data INF2 and the control data INFC2 based on the data signal S22, and also generates the control signal CTL1. The receiving unit 40 starts such a receiving operation based on the detection signal DET2.

  The processing unit 24 performs predetermined processing based on the data INF2 and the control data INFC2.

  The connection detection unit 25 detects whether or not the transmission device 10 and the reception device 20 are connected to each other. Specifically, whether or not the transmission device 10 and the reception device 20 are connected to each other based on whether or not the connection detection unit 25 is connected to the connection detection unit 15 of the transmission device 10 via the electric wire 902. Is supposed to detect. The connection detection unit 25 notifies the reception unit 40 of the detection result using the detection signal DET2.

  The transmission unit 26 transmits the control signal CTL1 to the transmission device 10 via the electric wire 903.

  Here, the control signal CTL1 corresponds to a specific example of “first level control signal” in the present disclosure. The control signal generation unit 50 corresponds to a specific example of “first generation unit” in the present disclosure. The input level detection unit 51 corresponds to a specific example of “first detection unit” in the present disclosure. The control signal CTLA corresponds to a specific example of “first control signal” in the present disclosure. The control signal generation unit 60 corresponds to a specific example of “second generation unit” in the present disclosure. The error rate estimation unit 61 corresponds to a specific example of a “second detection unit” in the present disclosure. The control signal CTLB corresponds to a specific example of “second control signal” in the present disclosure. The control signal generation unit 47 corresponds to a specific example of “control signal generation unit” in the present disclosure.

[Operation and Action]
Next, the operation and action of the communication system 1 according to the present embodiment will be described.

(Overview of overall operation)
First, an overall operation overview of the communication system 1 will be described with reference to FIGS. In the transmission device 10, the connection detection unit 15 (FIG. 1) generates the detection signal DET1 by detecting whether the transmission device 10 and the reception device 20 are connected to each other. The receiving unit 16 receives the control signal CTL1 transmitted from the receiving device 20 via the electric wire 903. The processing unit 12 generates data INF1 and control data INFC1 by performing predetermined processing. The transmission unit 30 starts a transmission operation based on the detection signal DET1. Specifically, the error correction encoding unit 31 (FIG. 2) generates an error correction code of the data INF1 by performing an error correction encoding process based on the data INF1, and uses the generated error correction code as the data INF1. At the same time, it is supplied to the frame generation unit 33. The error correction encoding unit 32 generates an error correction code of the control data INFC1 by performing error correction encoding processing based on the control data INFC1, and sends the generated error correction code to the frame generation unit 33 together with the control data INFC1. Supply. The frame generation unit 33 generates a frame based on the data INF1 and the error correction code of the data INF1, and the control data INFC1 and the error correction code of the control data INFC1, and emits the frame using the data signal S30. To the unit 14. The output level control unit 36 controls the output level Lout of the optical signal output from the light emitting unit 14 based on the control signal CTL1 using the signal S36. The light emitting unit 14 (FIG. 1) converts the electrical signal (data signal S30) into an optical signal, outputs the optical signal, and changes the output level Lout of the optical signal based on the signal S36.

  In the reception device 20, the connection detection unit 25 (FIG. 1) generates the detection signal DET2 by detecting whether or not the transmission device 10 and the reception device 20 are connected to each other. The light receiving unit 22 generates the data signal S22 by converting the optical signal transmitted from the transmission device 10 into an electrical signal. The receiving unit 40 starts a receiving operation based on the detection signal DET2. Specifically, the control signal generator 50 (FIG. 3) generates the control signal CTLA based on the data signal S22. The frame separation unit 41 extracts the data and the error correction code of the data from the frame included in the data signal S22, supplies the data and the error correction code of the data to the error correction decoding unit 42, and also receives the control data and the error correction code of the control data from the frame. This is taken out and supplied to the error correction decoding unit 43. The error correction decoding unit 42 generates the data INF2 by performing error correction decoding processing based on the data supplied from the frame separation unit 41 and the error correction code of the data, and the error in a predetermined period. The number is counted, and the count result is supplied to the control signal generator 60. The error correction decoding unit 43 generates control data INFC2 by performing error correction decoding processing based on the control data supplied from the frame separation unit 41 and the error correction code of the control data, The number of errors in the period is counted, and the count result is supplied to the control signal generator 60. The control signal generation unit 60 generates the control signal CTLB based on the count result supplied from the error correction decoding units 42 and 43. The control signal generator 47 generates a control signal CTL1 based on the control signals CTLA and CTLB. The processing unit 24 (FIG. 1) performs a predetermined process based on the data INF2 and the control data INFC2. The transmission unit 26 transmits the control signal CTL1 to the transmission device 10 via the electric wire 903.

(Detailed operation)
Next, the control operation of the output level Lout of the optical signal output from the light emitting unit 14 will be described in detail.

  FIG. 5 illustrates an operation example of the communication system 1. In the communication system 1, after the transmission device 10 and the reception device 20 are connected to each other, first, the output level Lout is controlled based on the control signal CTLA, and then the output level Lout is controlled based on the control signal CTLB. . This operation will be described in detail below.

  First, the communication system 1 performs connection detection (step S1). Specifically, the connection detection unit 15 of the transmission device 10 detects that it is connected to the connection detection unit 25 via the electric wire 902, and notifies the transmission unit 30 of the detection result using the detection signal DET1. . Thereby, the connection detection unit 15 instructs the transmission unit 30 to start the transmission operation. Similarly, the connection detection unit 25 of the reception device 20 detects that it is connected to the connection detection unit 15 via the electric wire 902 and notifies the reception unit 40 of the detection result using the detection signal DET2. Thereby, the connection detection unit 25 instructs the reception unit 40 to start the reception operation. If the connection detection units 15 and 25 cannot detect the connection, the process does not proceed to the next step S2.

  Next, the transmission device 10 sets the output level Lout to the initial output level Lo_init, and transmits an optical signal (step S2). Specifically, first, the error correction encoding unit 31 performs an error correction encoding process based on the data INF1, thereby generating an error correction code of the data INF1, and the generated error correction code is framed together with the data INF1. It supplies to the production | generation part 33. FIG. Similarly, the error correction encoding unit 32 generates an error correction code of the control data INFC1 by performing error correction encoding processing based on the control data INFC1, and generates a frame of the generated error correction code together with the control data INFC1. To the unit 33. Then, the frame generation unit 33 generates a frame based on the data INF1 and the error correction code of the data INF1, the control data INFC1 and the error correction code of the control data INFC1, and uses the data signal S30. To the light emitting unit 14. The light emitting unit 14 generates an optical signal based on the data signal S30. At that time, the output level control unit 36 sets the output level Lout of the optical signal to the initial output level Lo_init.

  Next, the communication system 1 controls the output level Lout of the optical signal output from the light emitting unit 14 based on the input level Lin of the optical signal received by the light receiving unit 22 (step S3).

  FIG. 6 shows the control operation of the output level Lout in step S3. In FIG. 6, the horizontal axis represents the output level Lout, and the vertical axis represents the input level Lin. A characteristic W1 indicates the relationship between the output level Lout and the input level Lin in the communication system 1. Thus, in the communication system 1, when the output level Lout becomes larger than a certain level Loffset, the input level Lin changes. This level Loffset corresponds to the loss due to the optical transmission line (optical fiber 901 and connectors 91, 92, 11, 21), the minimum light receiving sensitivity of the light receiving unit 22, and the like. Moreover, it changes according to the connection status when the user connects the transmission cable 90 to the transmission device 10 and the reception device 20. That is, for example, when there is dust or the like in the vicinity of the optical terminal of the connector, the loss increases, so the value Loffset increases.

  First, in the receiving device 20, the input level detecting unit 51 of the control signal generating unit 50 detects the input level Lin (Li_det) of the optical signal received by the light receiving unit 22 based on the data signal S22. In this example, the input level Li_det is higher than the target input level Li_target1. The input level comparison unit 53 obtains a difference DA between the input level Li_det and the target input level Li_target1. Then, the loop filter 54 generates the control signal CTLA by smoothing the difference DA. The control signal generator 47 outputs the control signal CTLA as the control signal CTL1. That is, since the predetermined time t_timer has not elapsed since the timing at which the transmission device 10 and the reception device 20 are connected to each other, the control signal generation unit 47 outputs the control signal CTLA as the control signal CTL1. Then, the transmission unit 26 transmits the control signal CTL1 to the transmission device 10 via the electric wire 903.

  The receiving unit 16 of the transmitting device 10 receives the control signal CTL1 via the electric wire 903. Then, the output level control unit 36 changes the output level Lout based on the control signal CTL1. As a result, the input level Lin changes toward the target input level Li_target1.

  In step S3, the error correction decoding unit 42 generates data INF2 by performing error correction decoding processing, and counts the number of errors in a predetermined period. Similarly, the error correction decoding unit 43 generates control data INFC2 by performing error correction decoding processing, and counts the number of errors in a predetermined period. These count numbers are used in step S5 described later.

  The communication system 1 repeats this operation until a predetermined time t_timer elapses from the timing at which the transmission device 10 and the reception device 20 are connected to each other (step S4). Thereby, in the communication system 1, negative feedback control is performed, and the input level Lin gradually approaches the target input level Li_target1.

 When the predetermined time t_timer elapses, the communication system 1 controls the output level Lout of the optical signal output from the light emitting unit 14 based on the error rate BER (step S5).

  FIG. 7 shows the control operation of the output level Lout in step S5. In FIG. 7, the horizontal axis represents the input level Lin, and the vertical axis represents the error rate BER. As indicated by the characteristic W2, the error rate BER can be expressed as a function of the input level Lin.

  First, in the receiving apparatus 20, the error rate estimation unit 61 of the control signal generation unit 60 estimates the error rate BER (BER_est) in the communication system 1 based on the count results supplied from the error correction decoding units 42 and 43. To do. In this example, the error rate BER_est is lower than the target error rate BER_target. The input level comparison unit 63 converts the error rate BER_est to the input level Lin (Li_est) based on the characteristic W2, and converts the target error rate BER_target to the input level Lin (target input level Li_target2). A difference DB with respect to the target input level Li_target2 is obtained. Then, the loop filter 64 generates the control signal CTLB by smoothing the difference DB. The control signal generator 47 outputs the control signal CTLB as the control signal CTL1. That is, since the predetermined time t_timer has elapsed from the timing at which the transmission device 10 and the reception device 20 are connected to each other, the control signal generation unit 47 outputs the control signal CTLB as the control signal CTL1. Then, the transmission unit 26 transmits the control signal CTL1 to the transmission device 10 via the electric wire 903.

  The receiving unit 16 of the transmitting device 10 receives the control signal CTL1 via the electric wire 903. Then, the output level control unit 36 changes the output level Lout based on the control signal CTL1. As a result, the input level Lin changes toward the target input level Li_target2.

  As long as the connection between the transmission device 10 and the reception device 20 is detected, the communication system 1 repeats the operation of step S5 (step S6). Thereby, in the communication system 1, negative feedback control is performed, and the input level Lin converges near the target input level Li_target2.

 Then, when the connection between the transmission device 10 and the reception device 20 is disconnected, this flow ends.

  Thus, in the communication system 1, the output level Lout is controlled. As a result, the output depends on the loss due to the optical transmission path (optical fiber 901 and connectors 91, 92, 11, 21), the connection status when the user connects the transmission cable 90 to the transmitter 10 and the receiver 20, and the like The level Lout can be appropriately controlled. That is, for example, when such control of the output level Lout is not performed, there can be a method of setting the output level Lout high so that normal communication can be performed in any case. However, in such a case, power consumption increases, and there is a possibility that the laser diode of the light emitting unit 14 is further deteriorated. In addition, when an optical signal leaks from the optical fiber 901 for some reason, an optical signal with a high output level Lout hits the user and the safety is impaired. On the other hand, in the communication system 1, since the output level Lout is controlled, the power consumption can be reduced and the deterioration of the laser diode can be suppressed. Further, even when an optical signal leaks from the optical fiber 901 due to some circumstances, the output level Lout of the optical signal can be suppressed, so that safety can be improved.

  In the communication system 1, the output level Lout is controlled based on the input level Lin of the optical signal received by the light receiving unit 22 at a predetermined time t_timer after the start of communication. Thereby, in the communication system 1, the output level Lout can be controlled in a short time. That is, for example, when the output level Lout is controlled on the basis of the error rate BER, it takes a certain amount of time to estimate the error rate BER, so that it becomes slow to start controlling the output level Lout. On the other hand, in the communication system 1, since the output level Lout is controlled based on the input level Lin, the control of the output level Lout can be started immediately after the light receiving unit 22 receives the optical signal. The output level Lout can be controlled.

  In the communication system 1, the output level Lout is controlled based on the error rate BER after a predetermined time t_timer has elapsed after the start of communication. Thereby, in the communication system 1, the output level Lout can be controlled with high accuracy. That is, for example, when the output level Lout is controlled based on the input level Lin of the optical signal received by the light receiving unit 22, it is not possible to directly know how much the error rate BER is actually. There is a possibility that the rate BER becomes low and the communication quality deteriorates. On the other hand, in the communication system 1, since the output level Lout can be controlled so that the error rate BER becomes a desired value, the output level Lout can be controlled with high accuracy.

  In this way, in the communication system 1, the output level Lout is controlled based on the input level Lin of the optical signal received by the light receiving unit 22 and the error rate BER. Can be controlled.

[effect]
As described above, since the output level is controlled in this embodiment, power consumption can be reduced, deterioration of the laser diode can be suppressed, and safety can be improved.

  In the present embodiment, since the output level is controlled based on the input level of the optical signal received by the light receiving unit and the error rate, the output level can be controlled in a short time and with high accuracy.

[Modification 1]
In the above embodiment, the control signal generation unit 47 generates the control signal CTL1 by switching the control signals CTLA and CTLB in a time division manner, but the present invention is not limited to this. For example, as in the control signal generation unit 47B shown in FIG. 8, the upper bits of the control signal CTLA are changed to the upper bits of the control signal CTL1, and the lower bits of the control signal CTLB are changed to the lower bits of the control signal CTL1. The signal CTL1 may be generated. In this case, after starting communication, first, the control signal generation unit 50 generates the control signal CTLA. At this time, the control signal generation unit 60 does not generate the control signal CTLB yet because it requires a certain amount of time to estimate the error rate BER. Therefore, the control signal CTL1 generated by the control signal generation unit 47B includes only the upper bits of the control signal CTLA. Thereafter, the control signal generation unit 60 generates the control signal CTLB after estimating the error rate BER. As a result, the control signal CTL1 generated by the control signal generation unit 47B includes the upper bits of the control signal CTLA and the lower bits of the control signal CTLB.

[Modification 2]
In the above embodiment, the communication system 1 is configured using the transmission device 10 and the reception device 20, but the communication system 1 is not limited to this. For example, two communication devices capable of transmitting and receiving data signals are used instead. You may comprise a communication system using. Below, this modification is demonstrated in detail.

  FIG. 9 illustrates a configuration example of the communication system 2 according to the present modification. The communication system 2 includes a transmission cable 90D and communication devices 70 and 80. The transmission cable 90D has optical fibers 901 and 904. The optical fiber 901 transmits a data signal from the communication device 70 to the communication device 80. The optical fiber 904 transmits a data signal from the communication device 80 to the communication device 70.

  The communication device 70 includes a connector 11, a processing unit 72, a transmission unit 30, a light emitting unit 14, a light receiving unit 76, a receiving unit 130, a processing unit 78, and a connection detection unit 15. The communication device 80 includes the light receiving unit 22, the receiving unit 40, the processing unit 84, the processing unit 88, the transmission unit 140, the light emitting unit 86, and the connection detection unit 25.

  Similar to the processing unit 12 according to the above-described embodiment, the processing unit 72 of the communication device 70 performs predetermined processing to generate data INF1 and control data INFC1, and transmits the data INF1 and control data INFC1 to the transmission unit 30. To supply. At this time, the processing unit 72 generates control data INFC1 based on the control signal CTL2 supplied from the receiving unit 130. The control signal CTL2 is a signal for controlling the output level Lout of the optical signal output from the light emitting unit 86 of the communication device 80.

  The processing unit 84 of the communication device 80 performs predetermined processing based on the data INF2 and the control data INFC2, similarly to the processing unit 24 according to the above embodiment. At this time, the processing unit 84 supplies a control signal CTL2 included in the control data INFC2 to the transmission unit 140.

  Similar to the processing unit 72 of the communication device 70, the processing unit 88 generates data INF3 and control data INFC3 by performing predetermined processing, and supplies the data INF3 and control data INFC3 to the transmission unit 140. . At this time, the processing unit 88 generates control data INFC3 based on the control signal CTL1 supplied from the receiving unit 40.

  Similar to the transmission unit 30 of the communication device 70, the transmission unit 140 generates the data signal S140 based on the data INF3, the control data INFC3, and the detection signal DET2, and generates the control signal CTL2 supplied from the processing unit 84. Based on this, the output level Lout of the optical signal output from the light emitting unit 86 is controlled using the signal S146.

  Similarly to the light emitting unit 14 of the communication device 70, the light emitting unit 86 converts the electrical signal (data signal S140) into an optical signal, outputs the optical signal, and outputs the optical signal based on the signal S146. Lout is changed.

  Similar to the light receiving unit 22 of the communication device 80, the light receiving unit 76 of the communication device 70 generates a data signal S76 by converting the optical signal transmitted from the communication device 80 into an electrical signal.

  Similarly to the receiving unit 40 of the communication device 80, the receiving unit 130 generates the data INF4 and the control data INFC4 based on the data signal S76 and the detection signal DET1, and also generates the control signal CTL2.

  Similar to the processing unit 84 of the communication device 80, the processing unit 78 performs predetermined processing based on the data INF4 and the control data INFC4. At that time, the processing unit 78 supplies a control signal CTL1 included in the control data INFC4 to the transmission unit 30.

  Here, the control signal CTL1 corresponds to a specific example of “first level control signal” in the present disclosure. The control signal CTL2 corresponds to a specific example of “second level control signal” in the present disclosure.

  FIG. 10A shows an operation when controlling the output level Lout of the optical signal output from the light emitting unit 14 of the communication device 70. In FIG. 10A, signals particularly important in this operation are indicated by solid lines, and other signals are indicated by broken lines. In this case, the reception unit 40 of the communication device 80 supplies the control signal CTL1 to the transmission unit 30 of the communication device 70 via the optical fiber 904. Thereby, in the communication system 2, the output level Lout of the optical signal output from the light emission part 14 is controlled similarly to the communication system 1 which concerns on the said embodiment.

  FIG. 10B illustrates an operation in the case of controlling the output level Lout of the optical signal output from the light emitting unit 86 of the communication device 80. In FIG. 10B, signals particularly important in this operation are indicated by solid lines, and other signals are indicated by broken lines. In this case, the reception unit 130 of the communication device 70 supplies the control signal CTL2 to the transmission unit 140 of the communication device 80 via the optical fiber 901. Thereby, in the communication system 2, the output level Lout of the optical signal output from the light emission part 86 is controlled similarly to the communication system 1 which concerns on the said embodiment.

  While the present technology has been described with the embodiment and some modifications, the present technology is not limited to these embodiments and the like, and various modifications can be made.

  For example, in the above embodiment, the control signal generator 47 is provided with the timer 49 for generating the signal SEL, but the present invention is not limited to this. Instead of this, for example, a signal generation unit that sets the signal SEL to a low level until the control signal CTLB is generated and sets the signal SEL to a high level after the control signal CTLB is generated may be provided.

  In addition, the effect described in this specification is an illustration to the last, and is not limited, Moreover, there may exist another effect.

  In addition, this technique can be set as the following structures.

(1) a receiving unit that generates a first level control signal based on the input level of the first data signal and the number of errors;
A communication device comprising: a transmission unit that transmits the first level control signal.

(2) The receiving unit
A first generator for generating a first control signal based on the input level;
A second generator for generating a second control signal based on the number of errors;
The communication device according to (1), further comprising: a level control signal generation unit that generates the first level control signal based on the first control signal and the second control signal.

(3) The level control signal generation unit generates the first level control signal by switching the first control signal and the second control signal in a time-sharing manner. Communication device.

(4) The level control signal generator outputs the first control signal as the first level control signal in the first period, and the second control period in the second period following the first period. The communication apparatus according to (3), wherein the control signal is output as the first level control signal.

(5) The first control signal and the second control signal are digital codes,
The level control signal generation unit, based on a predetermined number of bits of the plurality of bits of the first control signal and a predetermined number of bits of the plurality of bits of the second control signal, The communication device according to (2), wherein the first level control signal is generated.

(6) The level control signal generation unit is configured to perform a predetermined number of bits from the most significant bit among the plurality of bits of the first control signal and a predetermined number from the least significant bit among the plurality of bits of the second control signal. The communication device according to (5), wherein the first level control signal is generated based on a number of bits.

(7) The first generation unit includes a first detection unit that detects the input level. Based on the input level detected by the first detection unit and a predetermined input level, the first generation unit The communication device according to any one of (2) to (6).

(8) The second generation unit includes a second detection unit that detects an error rate based on the number of errors, and determines the second control signal based on the error rate and a predetermined error rate. The communication device according to any one of (2) to (7).

(9) The first data signal includes an error correction code,
The communication device according to any one of (1) to (8), wherein the reception unit obtains the number of errors based on the error correction code.

(10) The first data signal includes a second level control signal,
The transmission unit according to any one of (1) to (9), wherein the transmission unit transmits a second data signal including the first level control signal at an output level corresponding to the second level control signal. Communication device.

(11) The communication device according to (10), wherein the transmission unit transmits the second data signal via a laser diode.

(12) The communication device according to (1) to (11), wherein the reception unit receives the first data signal via a photodiode.

(13) A first receiving unit that receives a first level control signal and a first transmitting unit that transmits a first data signal at an output level corresponding to the first level control signal. A communication device of
A second receiver for receiving the first data signal and generating the first level control signal based on an input level and the number of errors of the first data signal; and the first level control A communication system comprising: a second transmission unit that transmits a signal; and a second communication device having the second transmission unit.

(14) causing the first communication device to receive the first level control signal, and to transmit the first data signal at an output level corresponding to the first level control signal;
The second communication apparatus receives the first data signal, and generates the first level control signal based on the input level and the number of errors of the first data signal, and the first level A communication method that transmits control signals.

  DESCRIPTION OF SYMBOLS 1, 2 ... Communication system, 10 ... Transmission apparatus, 11 ... Connector, 12 ... Processing part, 14 ... Light emission part, 15 ... Connection detection part, 16 ... Reception part, 20 ... Reception apparatus, 21 ... Connector, 22 ... Light reception part , 24 ... processing unit, 25 ... connection detection unit, 26 ... transmission unit, 30 ... transmission unit, 31, 32 ... error correction coding unit, 33 ... frame generation unit, 34 ... initial output level storage unit, 35 ... output level Range storage unit 36 ... Output level control unit 40 ... Reception unit 41 ... Frame separation unit 42,43 ... Error correction decoding unit 47 ... Control signal generation unit 48 ... Selector 49 ... Timer 50,60 ... control signal generation unit, 51 ... input level detection unit, 52 ... target input level storage unit, 53 ... input level comparison unit, 54 ... loop filter, 61 ... error rate estimation unit, 62 ... target error rate storage unit, 63 ... Input level comparison unit, 6 ... loop filter, 70, 80 ... communication device, 72 ... processing unit, 76 ... light receiving unit, 78 ... processing unit, 84 ... processing unit, 86 ... light emitting unit, 88 ... processing unit, 90, 90D ... transmission cable, 130 ... Receiver 140, Transmitter 901, 904 Optical fiber, 902, 903 Electric wire, BER, BER_est Error rate, CTL1, CTL2, CTLA, CTLB Control signal, DA, DB Difference, DET1, DET2 Detection Signal, INF1 to INF4 ... data, INFC1 to INFC4 ... control data, Lin, Li_det, Li_est ... input level, Li_target1, Li_target2 ... target input level, Lout, Lo_init ... output level, Lo_range ... range, S22, S30, S76, S140 Data signal, SEL ... signal, S36, S146 ... signal.

Claims (14)

A receiving unit that generates a first level control signal based on an input level of the first data signal and the number of errors;
A communication device comprising: a transmission unit that transmits the first level control signal. The receiver is
A first generator for generating a first control signal based on the input level;
A second generator for generating a second control signal based on the number of errors;
The communication apparatus according to claim 1, further comprising: a level control signal generation unit that generates the first level control signal based on the first control signal and the second control signal. The communication device according to claim 2, wherein the level control signal generation unit generates the first level control signal by switching the first control signal and the second control signal in a time division manner. The level control signal generation unit outputs the first control signal as the first level control signal in a first period, and the second control signal in a second period following the first period. The communication apparatus according to claim 3, wherein the first level control signal is output. The first control signal and the second control signal are digital codes,
The level control signal generation unit, based on a predetermined number of bits of the plurality of bits of the first control signal and a predetermined number of bits of the plurality of bits of the second control signal, The communication device according to claim 2, wherein the first level control signal is generated. The level control signal generation unit includes a predetermined number of bits from the most significant bit of the plurality of bits of the first control signal and a predetermined number of bits from the least significant bit of the plurality of bits of the second control signal. The communication device according to claim 5, wherein the first level control signal is generated based on: The first generation unit includes a first detection unit that detects the input level, and the first control signal is based on the input level detected by the first detection unit and a predetermined input level. The communication device according to claim 2. The second generation unit includes a second detection unit that detects an error rate based on the number of errors, and generates the second control signal based on the error rate and a predetermined error rate. Item 3. The communication device according to Item 2. The first data signal includes an error correction code;
The communication apparatus according to claim 1, wherein the reception unit obtains the number of errors based on the error correction code. The first data signal includes a second level control signal;
The communication apparatus according to claim 1, wherein the transmission unit transmits a second data signal including the first level control signal at an output level corresponding to the second level control signal. The communication device according to claim 10, wherein the transmission unit transmits the second data signal via a laser diode. The communication device according to claim 1, wherein the receiving unit receives the first data signal via a photodiode. 1st communication apparatus which has the 1st receiving part which receives the 1st level control signal, and the 1st transmitting part which transmits the 1st data signal with the output level according to the 1st level control signal When,
A second receiver for receiving the first data signal and generating the first level control signal based on an input level and the number of errors of the first data signal; and the first level control A communication system comprising: a second transmission unit that transmits a signal; and a second communication device having the second transmission unit. Causing the first communication device to receive the first level control signal and to transmit the first data signal at an output level corresponding to the first level control signal;
The second communication apparatus receives the first data signal, and generates the first level control signal based on the input level and the number of errors of the first data signal, and the first level A communication method that transmits control signals.

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